Abstract: :
Purpose: To study the relationship between keratoconus and axialmyopia.Methods: We prospectively studied refraction and ocularbiometry in 50 consecutive keratoconic eyes and 50 emmetropiceyes. Biometric data (including posterior segment length, cornealradius of curvature) were obtained by echography, Orbscan, andultrasonic pachymetry. Keratoconus were classified using Amslerclassification. The origin of myopia (corneal or axial) in thekeratoconus group was determined using the regression betweenvitreous length and corneal radius of curvature in the emmetropicgroup.Results: The posterior segment length is significantlygreater in the keratoconus group than in the emmetropic group(16.78 mm versus 16.03 mm p< 0.001). Posterior segment lengthshows no significant correlation with corneal ectasia parameters(corneal radius of curvature, pachymetry, and Amsler classification;p>0.10).In the keratoconus group, the cornea is responsiblefor 60% of the myopia in stade 1 or 2, 78% in stade 3, and in91% in stade 4.Conclusions: Keratoconus present a significantrelationship with axial myopia.